1. Field of the Invention
The present invention relates to backlight modules and, more particularly, backlight modules employing reflection control elements.
2. Discussion of Related Art
A liquid crystal material cannot illuminate by itself, so a typical liquid crystal display needs a backlight module to provide a uniform illumination, if sufficient ambient light is not always readily available. The performance of the backlight module mainly depends on a light guide plate employed therein. In operation, light emitted from a light source enters the light guide plate, is ten reflected by a reflective plate, and finally exits from a light-emitting surface of the light guide plate. With the aid of a diffusing plate and a prism plate, the light guide plate can generally provide a uniform luminance.
A typical backlight module includes a light guide plate having a light incident surface, a bottom surface and a light-emitting surface. The backlight module further includes lamps (i.e., a light source) disposed adjacent the light incident surface and a reflective plate disposed under the bottom surface. A diffusing plate and a prism plate are disposed on the light-emitting surface in the order of from bottom to top.
The reflective plate is used for reflecting light beams from the light sources and the light guide plate. The reflective plate typically includes a substrate and a reflective layer formed thereon. The reflective layer can be formed by a coating process. However, when the backlight module is in use, an elongate portion of the light-emitting surface of the light guide plate is generally over-illuminated. As a result, a corresponding elongate region, with a breadth of 3˜4 micrometers, of the liquid crystal display screen tends to display an unduly high brightness, thereby impairing the visual effect of the liquid crystal display screen.
Therefore, a heretofore-unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies associated with light guide plates and the backlight modules using such light guide plates.